| Abstract:The Linglong Yanshanian metasomatic type granite is a crust-source granite formed by metasomatism of metamorphic rocks of Jiaodong Group under the driving force of structural activity and the action of coexistent remelted gralite magma, and the Linglong gold deposit occurs at the northeastern end of this rock body. Faults are quite developed in the rook body: the NEE-NE trending fault system which experienced strong ductile shearing at the early stage and brittle fracturing at the late stage, is the major ore-controlling and ore-hosting structure; the NNE-and NW-trending faults, belonging to brittle faults, were formed comparatively late and frequently destroyed orebodies. The evolution of faults is obviously characterized by stages. When the rock body underwent diapiric emplacement, the granite was in a plastic quasisolid state and formed a series of ductile shear zones as aresult of compression, thus developing extensively plastic deformation flow, folds, crenulation, kinks, subgrains, pressure solution, flame-like rheological quartz aggregate crystals, recrystallization, abnormal extinction and mylonitizatization with the falling of temperature and plasticity of the rook body, brittle faults occurred in succession under the same stress field, and were frequently superposed on the ductile shear zone. Under the strong dynamothermal action, metallogenic substances of the source rock were activated and transferred. Ductile-brittle-fractural shattered zones obviously control the formation and spatial distribution of gold deposits; the superposition localities of the ductile shear and the brittle fault seem especially favorable for ore formation, and are thus important criteria and the best positions for ore prospecting. |
